Abstract: Public opinion reversal events are a special kind of public opinion events. Studying the emotional evolution characteristics of public opinion reversal events is of great significance to the comprehensive management of complex public opinion events and the stabilization of the network ecology. By dividing the life cycle of a specific public opinion reversal event and combining with the subject content characteristics, we carried out the sentiment analysis to describe the emotional evolution features of the public opinion reversal event from time dimension and the space dimension.The results show that the emotional focus and emotional tendency of netizens in each life cycle of public opinion reversal events show a complex evolutionary trend, and there are differences in public opinion attention and emotional state in different time periods and regions. Compared with ordinary public opinion events, the emotional changes of public opinion reversal events before and after the reversal have distinct characteristics, and the emotional evolution process is closely related to the development trend of public opinion reversal events.

Key words: Public opinion reversal, Microblog, Topic analysis, Sentiment analysis, Temporal and spatial evolution